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Azorella Macquariensis
''Azorella macquariensis'', also known as Macquarie azorella or Macquarie cushions, is a species of cushion plant endemic to Australia’s subantarctic Macquarie Island. It was referred to the more widely distributed ''Azorella selago'' until 1989, when it was described as a separate species.Tasmanian Threatened Species Notesheet (2009) Description ''Azorella macquariensis'' is a perennial cushion-forming herb. Individuals form cushions and mats that may vary in size from a few centimetres to several metres in diameter and up to 60 cm in height. It is a keystone species dominating Macquarie's feldmark habitat, in which it is the only vascular plant, forming a major structural component of the vegetation. The feldmark community covers about half the island in the most wind-exposed areas of the plateau some 200–400 m above sea level. The plant flowers from December to February and fruit In botany, a fruit is the seed-bearing structure in flowering plants that is formed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cushion Plant
A cushion plant is a compact, low-growing, mat-forming plant that is found in alpine, subalpine, arctic, or subarctic environments around the world. The term "cushion" is usually applied to woody plants that grow as spreading mats, are limited in height above the ground (a few inches at most), have relatively large and deep tap roots, and have life histories adapted to slow growth in a nutrient-poor environment with delayed reproductivity and reproductive cycle adaptations. The plant form is an example of parallel or convergent evolution with species from many different plant families on different continents converging on the same evolutionary adaptations to endure the harsh environmental conditions.Went, F. W. (1971). Parallel evolution. ''Taxon'', 20(2/3): 197-226. Description Cushion plants form large, low-growing mats that can grow up to in diameter. The typical form is a compact mass of closely spaced stems with minimal apical dominance that terminate in individual rosettes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Endemism
Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsewhere. For example, the Cape sugarbird is found exclusively in southwestern South Africa and is therefore said to be ''endemic'' to that particular part of the world. An endemic species can be also be referred to as an ''endemism'' or in scientific literature as an ''endemite''. For example '' Cytisus aeolicus'' is an endemite of the Italian flora. '' Adzharia renschi'' was once believed to be an endemite of the Caucasus, but it was later discovered to be a non-indigenous species from South America belonging to a different genus. The extreme opposite of an endemic species is one with a cosmopolitan distribution, having a global or widespread range. A rare alternative term for a species that is endemic is "precinctive", which applies to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Australia
Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, smaller islands. With an area of , Australia is the largest country by area in Oceania and the world's List of countries and dependencies by area, sixth-largest country. Australia is the oldest, flattest, and driest inhabited continent, with the least fertile soils. It is a Megadiverse countries, megadiverse country, and its size gives it a wide variety of landscapes and climates, with Deserts of Australia, deserts in the centre, tropical Forests of Australia, rainforests in the north-east, and List of mountains in Australia, mountain ranges in the south-east. The ancestors of Aboriginal Australians began arriving from south east Asia approximately Early human migrations#Nearby Oceania, 65,000 years ago, during the Last Glacial Period, last i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Subantarctic
The sub-Antarctic zone is a region in the Southern Hemisphere, located immediately north of the Antarctic region. This translates roughly to a latitude of between 46° and 60° south of the Equator. The subantarctic region includes many islands in the southern parts of the Atlantic, Indian, and Pacific oceans, especially those situated north of the Antarctic Convergence. Sub-Antarctic glaciers are, by definition, located on islands within the sub-Antarctic region. All glaciers located on the continent of Antarctica are by definition considered to be Antarctic glaciers. Geography The sub-Antarctic region comprises two geographic zones and three distinct fronts. The northernmost boundary of the subantarctic region is the rather ill-defined Subtropical Front (STF), also referred to as the Subtropical Convergence. To the south of the STF is a geographic zone, the Subantarctic Zone (SAZ). South of the SAZ is the Subantarctic Front (SAF). South of the SAF is another marine zone, cal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Macquarie Island
Macquarie Island is an island in the southwestern Pacific Ocean, about halfway between New Zealand and Antarctica. Regionally part of Oceania and politically a part of Tasmania, Australia, since 1900, it became a Tasmanian State Reserve in 1978 and was inscribed as a UNESCO World Heritage Site in 1997. It was a part of Esperance Municipality until 1993, when the municipality was merged with other municipalities to form Huon Valley Council. The island is home to the entire royal penguin population during their annual nesting season. Ecologically, the island is part of the Antipodes Subantarctic Islands tundra ecoregion. Since 1948, the Australian Antarctic Division (AAD) has maintained a permanent base, the Macquarie Island Station, on the isthmus at the northern end of the island at the foot of Wireless Hill. The population of the base, constituting the island's only human inhabitants, usually varies from 20 to 40 people over the year. A heliport is located nearby. In Septemb ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Azorella Selago
''Azorella selago'' is a species of cushion plant native to the sub-Antarctic islands of the Southern Ocean, including the Crozet Islands, the Possession Islands, the Heard Island and McDonald Islands, the Kerguelen Islands, and the Prince Edward Islands. The closely related ''Azorella macquariensis'', which is endemic to Macquarie Island, was split from it taxonomically in 1989. ''A. selago'' is often a keystone species A keystone species is a species which has a disproportionately large effect on its natural environment relative to its abundance, a concept introduced in 1969 by the zoologist Robert T. Paine. Keystone species play a critical role in maintaini ... where it occurs and is well studied for its contribution to its native ecosystems. References selago Flora of Heard Island and McDonald Islands Flora of the Kerguelen Islands Flora of the Prince Edward Islands Taxa named by Joseph Dalton Hooker Plants described in 1845 {{FrenchSouthernTerritories-s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Feldmark
Feldmark, also spelt fjaeldmark (), is a plant community characteristic of sites where plant growth is severely restricted by extremes of cold and exposure to wind, typical of alpine tundra and subantarctic environments. Description Feldmark plant communities are characterised by scattered dwarf and prostrate plants, up to about in height, often with a mat or cushion habit, among patches of bare ground and exposed rock. Distribution Feldmark occurs in the least favourable situations for plant growth, including late-lying snowdrift areas on leeward slopes and cold, highly wind-exposed ridges. Because feldmark species are adapted to cold bare ground, some are able to colonise areas of severe erosion where the topsoil has been removed, leaving only a surface of broken rock or stones.. In areas with strong prevailing winds, expansion through layering on the sheltered sides of plants means that they may grow preferentially on the protected sides and gradually move downwind across th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vascular Plant
Vascular plants (), also called tracheophytes () or collectively Tracheophyta (), form a large group of land plants ( accepted known species) that have lignified tissues (the xylem) for conducting water and minerals throughout the plant. They also have a specialized non-lignified tissue (the phloem) to conduct products of photosynthesis. Vascular plants include the clubmosses, horsetails, ferns, gymnosperms (including conifers), and angiosperms (flowering plants). Scientific names for the group include Tracheophyta, Tracheobionta and Equisetopsida ''sensu lato''. Some early land plants (the rhyniophytes) had less developed vascular tissue; the term eutracheophyte has been used for all other vascular plants, including all living ones. Historically, vascular plants were known as "higher plants", as it was believed that they were further evolved than other plants due to being more complex organisms. However, this is an antiquated remnant of the obsolete scala naturae, and the term ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flower
A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants (plants of the division Angiospermae). The biological function of a flower is to facilitate reproduction, usually by providing a mechanism for the union of sperm with eggs. Flowers may facilitate outcrossing (fusion of sperm and eggs from different individuals in a population) resulting from cross-pollination or allow selfing (fusion of sperm and egg from the same flower) when self-pollination occurs. There are two types of pollination: self-pollination and cross-pollination. Self-pollination occurs when the pollen from the anther is deposited on the stigma of the same flower, or another flower on the same plant. Cross-pollination is when pollen is transferred from the anther of one flower to the stigma of another flower on a different individual of the same species. Self-pollination happens in flowers where the stamen and carpel mature at the same time, and are positi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fruit
In botany, a fruit is the seed-bearing structure in flowering plants that is formed from the ovary after flowering. Fruits are the means by which flowering plants (also known as angiosperms) disseminate their seeds. Edible fruits in particular have long propagated using the movements of humans and animals in a symbiotic relationship that is the means for seed dispersal for the one group and nutrition for the other; in fact, humans and many animals have become dependent on fruits as a source of food. Consequently, fruits account for a substantial fraction of the world's agricultural output, and some (such as the apple and the pomegranate) have acquired extensive cultural and symbolic meanings. In common language usage, "fruit" normally means the seed-associated fleshy structures (or produce) of plants that typically are sweet or sour and edible in the raw state, such as apples, bananas, grapes, lemons, oranges, and strawberries. In botanical usage, the term "fruit" also i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Azorella
''Azorella'' is a genus of flowering plants in the family Apiaceae, native to South America, New Zealand, southeastern Australia, and the islands of the Southern Ocean. They are low-growing dwarf mat-forming plants growing in high exposure on mountains and subantarctic coasts; with great age they may form rounded mounds of foliage up to 1 m high but are usually less than 10 cm high. Several species are grown as ornamental plants in rock gardens. Species , Plants of the World Online accepted 58 species: *''Azorella acaulis'' (Cav.) Drude *''Azorella albovaginata'' (Gillies & Hook.) G.M.Plunkett & A.N.Nicolas *''Azorella allanii'' (Cheeseman) G.M.Plunkett & A.N.Nicolas *''Azorella ameghinoi'' Speg. *''Azorella andina'' (Phil.) Drude *''Azorella aretioides'' (Kunth) Willd. ex DC. *''Azorella biloba'' (Schltdl.) Wedd. *''Azorella boelckei'' (Mathias & Constance) G.M.Plunkett & A.N.Nicolas *''Azorella burkartii'' (Mathias & Constance) G.M.Plunkett & A.N.Nicolas *''Azorella ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plants Described In 1989
Plants are predominantly photosynthetic eukaryotes of the kingdom Plantae. Historically, the plant kingdom encompassed all living things that were not animals, and included algae and fungi; however, all current definitions of Plantae exclude the fungi and some algae, as well as the prokaryotes (the archaea and bacteria). By one definition, plants form the clade Viridiplantae (Latin name for "green plants") which is sister of the Glaucophyta, and consists of the green algae and Embryophyta (land plants). The latter includes the flowering plants, conifers and other gymnosperms, ferns and their allies, hornworts, liverworts, and mosses. Most plants are multicellular organisms. Green plants obtain most of their energy from sunlight via photosynthesis by primary chloroplasts that are derived from endosymbiosis with cyanobacteria. Their chloroplasts contain chlorophylls a and b, which gives them their green color. Some plants are parasitic or mycotrophic and have lost the ability ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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